I am having the same problem! I'm glad someone posted about this before I did.

You are correct, it seems to be just multi-track games with the cdda files (audio tracks basically).

The images with one or two bins seem to play fine but the ones with many like Tekken, Twisted Metal, Cool Boarders 2 and others my modded PS1 can't read the music for some reason but in an emulator it works just fine. I wonder if it needs to be burnt a certain way for the actual system to read the music contained in these multi track images.